import numpy as np
arr = np.array([[1,2,3],[4,5,6],[7,8,9],[10,11,12]])
print('4*3的整数数组:\n',arr)
print('数组的ndim属性:',arr.ndim)
print('数组的shape属性:',arr.shape)
print('数组的size属性',arr.size)
print('数组的dtype属性',arr.dtype)